Lord Hutton said he was giving "urgent consideration" to taking legal action against the Sun after it leaked the conclusions of his report into the death of the Dr David Kelly.

Speaking at the end of his statement today, Lord Hutton said the leak was "all the more regrettable" given the steps that he had taken in the previous 24 hours to ensure that such a breach of security did not happen.

"I sought to ensure the contents of the report should remain confidential until it was published," he said.

"I gave advanced copies my report to [interested] parties 24 hours in advance of its publication. It is all the more regrettable that a newspaper published a report of some of my conclusions before I have published the full contents of my report.

"I am now giving urgent consideration to what investigative and legal action I should take in respect of the newspaper and its source."

Although Trevor Kavanagh, the Sun's political editor, said his source had "no axe to grind" and did not stand to gain financially or politically, the wording in this morning's paper is not so categorical - and does not rule out the possibility that the Sun paid for the leak.

Today's paper said: "The Hutton report was leaked to the Sun by someone who has no financial or vested interest in its outcome", suggesting someone else outside the world of politics and the BBC - and perhaps in the production or printing side - may have been a source.

The contents of the Sun's front page story were widely reported by other media outlets, even though it was not yet clear how accurate its predictions would prove to be. In the event, they proved very accurate.

Tony Blair said he was "very angry" about the leak, and his official spokesman has said that an inquiry into the leak should involve all parties involved. However, Lord Hutton will decide how to proceed with any investigation.

The Conservative leader, Michael Howard, has demanded a full inquiry into what he has branded the "quite disgraceful" leak.

Lord Hutton's office had been determined to prevent a leak of the report's findings, and had asked all of the interested parties who had received embargoed copies of the report to sign confidentiality agreements.

Suspicions that the paper had been handed the report's executive summary by a Labour source were immediately raised by commentators because of the paper's allegiance to the government during the war and the Hutton inquiry.

It launched a personal attack on reporter Andrew Gilligan and has always maintained that the BBC had cocked up and should have apologised when Alastair Campbell made its original complaints about the Today programme last June. It called for Gilligan to be sacked and branded him a "second-rate journalist who cannot be trusted".